.container{
    width: 100%;
    height: 100vh;
    background-color: white;
    position: relative;
}
#topbar{
    z-index: 999;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 6vh;
    background-color: green;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
#topbar-title{
    color: white;
    margin-left: 5vw;
    font-weight: bold;
}
#topbar-toggle{
    width: 8vw;
    height: 8vw;
    margin-right: 5vw;
}
#collapsible-panel{
    z-index: 99;
    width: 100%;
    height: 94vh;
    position: absolute;
    top: 6vh;
    display: none;
}
#collapsible-panel .menu{
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    height: 20vh;
    background-color: gainsboro;
}
.menu-item{
    width: 95%;
    height: 100%;
}
#content{
    width: 100%;
    /* 可改为auto */
    height: 94vh; 
    background-color: antiquewhite;
    position: absolute;
    top: 6vh;
    z-index: 1;
}
